Train-carried receiver for automatic train-control systems



\ Jan. 3, 1928. 1,655,006

C. H. ZIERDT TRAIN CARRIED RECEIVER FOR AUTOMATIC TRAIN CONTROL SYSTEMS Original Filed July 29. 1926 INVENTOR C.//- ZIKdY/T Patented Jan. 3, 1928.

UNITED STATES PATENT OFFICE.

CONRAD I-I. ZIERDT, OF ROSEDALE, PENN TOWNSHIP, ALLEGHENY COUNTY, PENNS-YL VANIA, ASSIGNOR TO THE UNION SWITCH Ca SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TRAIN-GARRIED RECEIVER FOR AUTOMATIC TRAIN-CONTROL SYSTEMS.

Original application filed July 29, 1926, Serial No. 125,658. Divided and this application filed November 22, 1927. Serial No. 234,977.

M invention relates to automatic train control systems, and particularly to systems in which train carried apparatus is controlled at least in part by alternating train controlling current which flows through the track rails in multiple. More particularly my invention relates to train carried receivers for use in such systems.

One object of my invention is the provision of a receiver which will supply energy to the train carried apparatus in accordance with the train controlling current in the track rails, but which will be substantially immune from alternating current flowing in adjacent transmission lines, track circuits, etc.

This application is a division of my co pending application, Serial #125,658, filed July 29, 1926, for train carried receivers for automatic train control systems.

1 will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view showing a portion of an automatic train control system including one form'ot receiver embodying my invention. Figure 2 is a front view of the receiver illustrated in Fig. 1.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a stretch of railway track, the rails being divided by means of insulated joints 2, to form a section. Connected across the rails at spaced points are two resistances 3 and 3 to the mid-points of which are connected the terminals of the secondary 5 of a trans former The primary 4; of the transformer T is supplied with alternating current from any suitable source, not shown in the drawing. In practice, the supply of current to the track rails will usually be controlled in accordance with traiiic conditions, but inasmuch as the controlling apparatus forms no part of the present invention it is omitted from the drawing. The current supplied by the transformer T flows through the track rails in multiple, that is, at any given instant it flows in the same direction in these rails. This current will be referred to as the loop current.

The reference character V designates a train on which is carried a receiver A placed between two cars transversely of the track rails and beneath the coupler. The receiver will usually be placed on the rear oi the tender or between the locomotive and tender on a steam train and between the first two cars of an electric train.

Referring now to Fig. 2, the receiver A comprises three elongated cores 12, 13 and 14- ot magnetizable material. The core 14 extends transversely across the trackway in a horizontal position substantially in the plane of the rails, and the cores 12 and 13 extend transversely across the two track rails 1 and 1 respectively, at acute angles with the horizontal in such a manner that the long axes of the cores intersect substantially in the coupler 11. The cores 12, 13 and .14 may be secured together by clamps l5 and 16 of non-magnetic material. The core 14 is provided with a coil 14, while cores 12 and 13 are provided with coils 12 and 13 respectively.

The dash line 18 represents the path taken by the flux resulting from the loop current flowing in the rails. This flux passes through the cores 12 and 13 and induces electromotive forces in the coils 12 and 13. Due to the potential drop along the rails caused by the loop current flowing in them, a portion of the loop current will flow through the metallic running gear of the train and the couplers connecting adjacent cars. The dot and dash line 17 represents the path taken by the flux resulting from the current in the coupler, which flux passes through the core 14, and induces an electromotive force in coil 14. Coils 12, 13 and 14 are connected in series in such manner that the electromotive forces induced in these coils by the currents flowing in the rails and the coupler are additive. lVith this arrangement the total voltage induced in the coils of the receiver is substantially constant and independent of the distribution of the loop currentbetween the rail and coupler.

by the electromotive force induced in coil l t by such foreigi'i illux.

The coils l2, 3 and 1-H are connected in series with a condenser (3 to form a pickup circuit B, and the whole circuit will usuallybetuned to resonance at the frequency of the current supplied by the trans'tormer T. The current from the pick-up circuit TB may be supplied to any suitable form 01? train carried governing apparatus here shown as an induction motor relay R. The relay R comprises a rotor 10 and two wind-- ings 8 and 9. The winding 8 may be supplied with energy from circuit B through an amplifier 7. The winding 9 may be supplied with energy from any suitable source which forms no part of the invention and is therefore omitted from the drawing.

It will thus be seen that I have provided a receiver which will utilize the loop current flowing in the track rails and the car couplers to operate relay R, but which will not supply energy to the relay in accordance "with stray fields set up by circuits which would otherwise interfere with the normal operation of the train carried apparatus.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made thereln wlthin the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention What I claim is:

1. A train carried receiver comprising two substantially straight magnetic cores mountedin inductive relation to the track rails, a

third magnetic core in inductive relation to a car coupler, and a coilon each of the cores, the three coils being connected in series and. so arranged that the electromotive lorces induced therein by currents flowing through the track rails andv the coupler in multiple are additive.

2. A train carried receiver comprising two substantially straight magnetic cores extending transversely over the track rails in acute angular relation to the horizontal, a third ma 'netic core in inductive relation with a car coupler, and a coil on each of the cores, the coils being connected in series and so arranged that the eleetromotive forces induced therein by currents flowing through the track rails and the coupler in multiple are additive.

3. A train carried receiver comprising a first core or magnetizablematerial extendingtransversely across the traclrway substantially in the plane of the rails, two other cores of magnetizable material extending transversely across the track rails respectively at acute angles *ith the horizontal in such manner that their long axes intersect substantially in a car coupler, and three coils, one on each core, and all connected in series in such manner that the electromotive forces induced therein by currents flowing through the track rails and the coupler in the same direction at any instant are additive.

In testimony whereof I affix my signature.

CONRAD I-I. ZIERDT, 

